Derestricting a Piaggio Typhoon 50


Ok first of all a couple of points;

1. I can't take any responsibility for any damage you do to yourself or your bike, I'm certainly no mechanic and make no guarantees that any of this information is correct.
2. It's up to you to make yourself legal on the road.

The reason I've made this page is primarily because I hate motorcycle dealers. I've been riding bikes for years (sports bikes to scooters) and have yet to find an honest dealer, if just one person manages to do this themeself and deny a dealer some money then this page has served it's purpose. A horrible generalisation I know but then I've had nothing but bad experiences. Even ringing around to find information about this I was lied to about where the restrictors were on a number of occassions and generally treated with disdain. Most likely because the average scooter rider is a teenager and they feel they can get away with it. If you're new to bike riding my advice would be to treat a bike with Full Service History the same as any other and do as much work yourself as possible.

Anyway enough of my moaning! As far as I'm aware there are only 2 restrictors on a Typhoon 50, there may be more/less but as noone was willing to offer me any concrete information I've had to figure this out myself. One is a gearing restrictor and the other is on the exhaust.


If you can't be bothered with this section then skip straight to the practical bit below. However if your'e having problems locating anything you might want to come back here as knowing the theory might help you along.

I believe the exhaust restrictor is the small tubular section that comes off the main pipe near the engine, I think it's there to cause turbulance in the air flow making the exhaust less efficient. I'm not 100% sure about this but as there's not alot you can do about it (it's welded on) it's not too important if I'm wrong. Mine did actually fall off so I've used some exhaust wrap and putty, I can't say I noticed much of a power gain but we are talking scooter. I think you'll find you'll be buying a decent exhaust before long anyway as the original exhaust lasts about 2 minutes in winter.

Now onto the gearing and removing this restrictor really does make a difference. Remember though that it's a gearing restriction, not a power restriction so the bike wont accelerate any faster, it'll just have a higher top speed. With this restrictor removed you're looking at roughly 35 uphill, 45 on the flat and 55 downhill(stock exhaust). The best way to explain the theory behind this restriction is comparing it to bicycle gears. On a bicycle you have a front and rear sprocket with numerous different sized chain rings front and rear. The chain jumps from one to another to make it harder/easier to push the pedals. If the chain is on the big ring at the front and the small ring at the back then the pedals are hardest to push, and if vice-versa they're easiest to push. Taking out the human element if the pedals have a maximum rate they can spin at the fastest a bicycle will travel will be in the hardest gear to push. Now if you imagine the same bicycle without it's biggest ring at the front in the same scenario the bikes theoritical top speed will have been reduced.
The gearing restrictor on your Piaggio does the same thing. The differences are that your Typhoon has a belt, not a chain, and the size of the ring at the back is fixed(size only changes at the front). Also because there's no chain there's no teeth involved and no seperate sprockets either. Instead it uses a system comprising of 2 cones(with the belt in between) that get closer and further appart causing the radius that the belt moves around to get smaller and larger(similar to a chain jumping from a smaller to larger ring etc). The gearing restrictor is a black plastic washer in the middle of these 2 cones. It prevents the cones coming fully together meaning the belt doesn't get to it's largest radius - and by now boys and girls we all know that the biggest radius at the front means a higher top speed! Hurrah and so endeth this crappily written totally confusing lesson. At least I know what I mean - on to actually doing it!


Now there is a part of doing this that I presume garages use a special tool for. The part I'm refering to is removing the nut in section 2, I've described the way I did it below, you can obviously improvise any way you like. Have a read through and if you feel you can't do this bit then you'll have to give the whole thing a miss. Rest assured if you can remove the nut in section 2 then it's plain sailing. The whole thing took me about 20 mins (probably would have taken 10 with the special tool) and costs 50 at a dealer.

What you'll need:

8mm socket wrench(preferably with extension).
15mm socket wrench.
A hammer.
Probably a large screwdriver and a friend for improvising in section 2 (IMPORTANT See update at bottom of page).

1. Remove the belt drive cover

On the left hand side of your bike(as you sit on it) you'll find the belt drive cover pictured below. Use your 8mm and remove the 15 bolts holding it on. Don't bother taking off the black cover or the kickstart lever, these will come off as one with the belt cover. You'll find once the 15 bolts are out that it's still attached quite strongly. This is because there are 2 tapets which are located below the 2 pink circles in the picture.

I found the best way to remove the cover once the bolts are out is use something like a screw driver or socket extension, put it through the wheel resting on a lip of metal on the cover, and drive with a hammer (see below picture). A combination of this and wiggling the cover with your hands will see it come off no bother.

2. Removing the dreaded nut! (IMPORTANT See update at bottom of page)

Once you have the belt drive cover off you'll be presented with the following:

Where you see the pink circle in the picture is actually the outer of the 2 cones for the gearing(see theory). The outer cone stays static while the inner cone moves in and out changing the final drive ratio. To get to the restrictor you need to remove the outer cone and to do this you need to remove the nut in the middle.

Just to give you an idea what the restrictor looks like at this stage put your head where the camera is in this photo and look where the pink arrow is pointing. You should see a black washer between the 2 cones (and below the belt) like the one in the second pic. Thats what we're looking to remove.

Back to the task at hand. Get your 15mm socket wrench out and give the nut a quick stab, you'll notice the whole cone turns when you try to undo it. To get the nut off you're going to have to stop the cone turning. The pink mark in the pic below is supposed to represent the area in which the teeth on the outside of the cone get close to the engine casing (the teeth are for the electric start). If you stick a big screwdriver in this area it prevents the cone from moving as the screwdriver/case/teeth meet. If you get a friend to hold the screwdriver and you gradually apply pressure to the nut it will come undone. You're obviously not forced to use this method, how you improvise is up to you but this is the best way I could think of.

3. Removing the restrictor and putting it back together

Unfortunately I don't have a picture of this as the photo came out virtually black. However this bit is extremely simple, just remove the outer cone, remove the black washer and put the outer cone back on again. Just a note of warning, don't be tempted to remove the inner cone (as I was), there are a number of bushes behind it waiting to drop all over the floor and it's a bit fiddly to put back together.

So thats it, you have the restrictor out, the black washer in your hand is responsible for taking that 15mph extra top end :) To put it back together just reverse the above process. Again the only tricky bit will be tightening the nut holding the outer cone on. I used the same method except I moved the screwdriver below the pink mark on prev photo as the cone is obviously being tightened in the other direction.

Good luck. If you have any suggestions, would like to link the page, need any help with the process or want someone to shout at feel free to drop me a mail:

UPDATE 11/07/05

I'd just like to say thanks for all the emails, it seems I wasn't alone in my dislike for dealers ;)
Again please feel free to email for advice and I will try & help you as much as I can.

I forget who emailed me about this now(thanks to whoever it was), but removing the nut in section 2 is actually much simpler and easier than I had originally thought. All you have to do is remove the plastic fan cover on the other side of the bike & get a spanner on the nut there - it goes straight through to the nut you have to undo.

Good luck!

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